- Byron Leftwich 's season is over after Tampa Bay put the backup quarterback on injured reserve with a sore right elbow.

CONCUSSIONS: Commissioner Roger Goodell sent a wide-ranging memo about concussions to NFL teams Tuesday, saying the co-chairmen of the league's committee on brain injuries have resigned and that he is examining potential rule changes "to reduce head impacts."

Goodell wrote that Dr. Ira Casson and Dr. David Viano , who have led the league committee on concussions since 2007, "have graciously offered to resign from those positions and to continue to assist the committee in its important work. We have accepted those resignations and are currently identifying their replacements."

Goodell said he wants to add new members "who will bring to the committee independent sources of expertise and experience in the field of head injuries."